Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
  • C07D201/02—Preparation of lactams
  • C07D201/08—Preparation of lactams from carboxylic acids or derivatives thereof, e.g. hydroxy carboxylic acids, lactones or nitriles

Definitions

• This invention relates to a process for the manufacture of l-actams and the corresponding polyamides.
• Molar ratio of lactone to ammonia or amine from 1:15 to 1:250.
• the lactones employed in the process of the invention contain from 4 to 8 carbon atoms; all of the carbon atoms may form part of the lactone ring or some of the carbon atoms may be present as alkyl substituents on the lactone ring.
• Suitable lactones are for example butyrolactone, valerolactone, caprolactone, methyl caprolactone and dimethyl caprolactone.
• the lactones employed in the process of the invention are the w-lactones.
• an amine preferably an aliphatic amine, a cycloaliphatic amine, an aromatic amine, or arylalkylamine containing from 1 to 8 carbon atoms
• an amine preferably an aliphatic amine, a cycloaliphatic amine, an aromatic amine, or arylalkylamine containing from 1 to 8 carbon atoms
• methylamiue ethylamine, n-propylamine, isopropylamine, n-butylaminc, iso-butylamine, sec-butylamine, n-pentylamine, n-hexylamine, cyclopentylamine, cyclohexylamine, aniline, toluidines or benzylamine.
• the derived lactams and polyamides contain a substituent on the nitrogen atom derived from the amine.
• Hydrogen is preferably employed in an amount of from 0.1 to 3 moles for each mol of ammonia.
• Suitable hydrogenation catalysts are any of those commonly employed in the hydrogenation of organic compounds such as R-aney nickel, nickel-on-kieselguhr, cobalton-kieselguhr, palladium-on-carbon or platinum oxide.
• the catalysts are usually employed in an amount of 0.05 part to 0.35 part per part of lac-tone.
• the product obtained by the process of the invention is a mixture containing a lactam and the corresponding polyamide, and may be worked up for example by fractional distillation to separate the lactam from the polyamide.
• the amino acid corresponding to the lactam may be recovered from the polyamide by hydrolysis for example with aqueous mineral acids, such as hydrochloric acid, and separation of the acid from the hydrolysis prodnet by evaporation.
• the residue obtained by evaporation may be purified by dissolving it in water and contacting the solution with an ion exchange resin.
• the acid may then be recovered by elution with water from the ion exchange resin.
• Suitable ion exchange resins are for example those of the basic type containing quaternary ammonium groups.
• Example 1 parts of e-caprolactone, 67 parts of anhydrous am m-onia, and 16 parts of Raney nickel catalyst are charged to a stainless steel autoclave, to which hydrogen is admitted at room temperature until the total pressure of ammonia and hydrogen is atmospheres.
• the temperature of the agitated reaction mixture then is raised to ca. 225 C. and maintained at this level for 8 hours when a maximum pressure of 190 atmospheres is developed.
• the final total pressure is found to be 79 atmospheres, corresponding to a hydrogen absorption of 0.94 mole per mole of caprolactone charged; it is then vented to atmosphere and, if required, unreacted ammonia may be recovered for re-use by condensation.
• the resulting residue is distilled under reduced pressure to give 3 fractions- (1) 8.7 parts of material B.P. 20-56 C148 mm., a colourless oil,
• Fraction 1 is largely water containing small amounts of hexamethylene dia-mine, hexamethylene imine and traces of other aliphatic bases.
• Fraction 2 is a mixture of hexamethylene diamine and e-capr-olactam. v
• the semi-crystalline colourless residue is shaken with 120 parts of hot ethanol, cooled to room temperature and 215 parts of ether are added. After keeping at 0 C. for 10 minutes, 16.8 parts of 6-a-minocaproic acid, M.P. 192-193 C. (benzoyl derivative M.P. 76 78 C.) are removed by filtration, washed with 50 parts of ether, and dried in vacuo.
• Example 2 The procedure of Example 1 is repeated with the following quantities of reactants: 75 parts of e-caprolactone, 300 parts of anhydrous ammonia, 16 parts of Raney nickel catalyst, and a total initial ammonia plus hydrogen pressure of 98 atmospheres.
• the heating period is 6 hours at 225 C. and the maximum pressure developed is 380 atmospheres.
• the final pressure of 85 atmospheres in the cooled autoclave corresponds to a hydrogen absorption of 0.90 mole per mole of caprolactone.
• the reaction product is removed from the autoclave with the aid of hot methanol, catalyst filtered oft and solvent evaporated. Distillation of the viscous residue afiords 3 fractions- (1) 1.87 parts of material B.P. 29 C./26 mm.-40 C./ 20 mm., a colourless oil,
• Fraction 1 is largely water containing small amounts of hexamethylene diamine and hexamethylene imine.
• Fraction 2 is a mixture of hexamethylene diamine and e-caprolactam.
• Fraction 3 is caprolactam, M.P. 58-61 C.
• Example 3 The procedure of Example 1 is repeated with the following quantities of reactants. 25 parts of e-caprolactone, 300 parts of anhydrous ammonia, 6 parts of Raney nickel catalyst, and a total initial ammonia-l-hydrogen pressure of 95 atmospheres. The heating period is 11.5 hours at 225 C. and the maximum pressure developed is 388 atmospheres. The final pressure of 90 atmospheres in the cooled autoclave corresponds to a hydrogen ab sorption of 1.11 moles per mole of caprolactone.
• the reaction product is removed from the autoclave with the aid of hot methanol, catalyst filtered off and solvent evaporated. Distillation of the viscous residue affords a trace of aqueous foreshots and then 3 fractions- (1)1.45 parts of material B.P. 90-125 C./16 mm., a colourless oil which crystallises on keeping,
• Fraction 1 is essentially hexamethylene diamine containing a little e-caprolactam.
• Fraction 2 is a mixture of hexamethylene diamine and caprolactam.
• Fraction 3 is e-caprolactam, M.P. 56-59 C.
• Example 4 The procedure of Example 1 is repeated with the following quantities of reactants: 37.5 parts of e-caprolactone, 300 parts of anhydrous ammonia, 8 parts of Raney nickel catalyst, and a total initial ammonia plus hydrogen pressure of 97 atmospheres.
• the heating period is 12 hours at 225 C. and the maximum pressure developed is 389 atmospheres.
• the final pressure of 90 atmospheres in the cooled autoclave corresponds to a hydrogen absorption of 1.02 moles per mole of caprolactone charged.
• the reaction product is removed from the autoclave with the aid of hot methanol, catalyst is filtered off and solvent evaporated. Distillation of the viscous residue afiords 3 fractions (1) 1.57 parts of material B.P. 104120 C./13.5 mm., a colourless oil which crystallises on keeping,
• Fraction 1 is essentially hexamethylene diamine containing a little e-caprolactam.
• Fraction 2 is a mixture of hexamethylene diamine and e-caprolactam.
• Fraction 3 is caprolactam, M.P. 53-54 C.
• Example 5 The same quantities of reactants are used as in Example 1 but the temperature of the agitated reaction mixture is raised to 272 C. and maintained at this level for 8 /2 hours when a maximum pressure of 270 atmospheres is developed. When the autoclave then is cooled to room temperature, the final total pressure is found to be 78 atmospheres corresponding to a hydrogen absorption of 1.02 moles per mole of caprolactone charged.
• the reaction product is removed from the autoclave with the aid of hot methanol, catalyst is filtered off and solvent evaporated. Distillation of the viscous residue affords 4 fractions- (1) 2.83 parts of material B.P. 20-58 C./25 mm., a colourless oil,
• Fraction 1 is largely water containing small amounts of hexamethylenediamine and hexamethylene imine.
• Fraction 2 contains hexamethylcnediamine and hexamethylene imine.
• Fraction 3 contains hexamethylenediamine, hexamethyene imine and e-caprolactam.
• Fraction 4 is e-caprolactam M.P. 53-56 C.
• the involatile distillation residue is essentially low molecular weight polycaprolactam.
• Example 6 The procedure of Example 2 is repeated except that 'y-butyrolactone replaces e-caprolactone.
• the product consists of 504 parts of 'y-butyrolactan, B.P. 134136 C./ 19 mm., accompanied by only a very little polymeric material.
• a process according to claim 1 wherein the molar ratio of lactone to the nitrogenous compound is from 1:15 to about 1:250.
• the nitrogenous compound is an amine selected from the group consisting of an aliphatic amine, a cycloaliphatic amine, an
• aromatic amine and an arylalkylamine containing from 1 to 8 carbon atoms.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Other In-Based Heterocyclic Compounds (AREA)
• Polyamides (AREA)

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Citations (3)

• 1964
  • 1964-03-04 GB GB9199/64A patent/GB1090803A/en not_active Expired
• 1965
  • 1965-02-26 US US435743A patent/US3342809A/en not_active Expired - Lifetime
  • 1965-03-02 BE BE660505A patent/BE660505A/xx unknown
  • 1965-03-03 CH CH297365A patent/CH449256A/de unknown
  • 1965-03-04 NL NL6502776A patent/NL6502776A/xx unknown
  • 1965-03-04 FR FR7987A patent/FR1425954A/fr not_active Expired

Patent Citations (3)

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